Dr Faustman said: “BCG is interesting because it brings into play so many areas of immunology that we as a community have been looking at for decades, including Tregs and the hygiene hypothesis.

“Repeat BCG vaccination appears to permanently turn on signature Treg genes, and the vaccine’s beneficial effect on host immune response recapitulates decades of human co-evolution with mycobacteria, a relationship that has been lost with modern eating and living habits.

WHAT IS THE DIFFERENCE BETWEEN TYPE 1 AND TYPE 2 DIABETES?

All types of diabetes cause blood glucose levels to be higher than normal, but the two different types do this in different ways.

The distinction lies in what is causing the lack of insulin – often described as the key, that allows glucose to unlock the door to the cells.

With type 1 diabetes, a person’s pancreas produces no insulin, but in type 2 cells in the body become resistant to insulin, so a greater amount of insulin is needed to keep blood glucose levels within a normal range.

Type 2 diabetes linked to obesity

Type 2 diabetes is the more common form of the disease – accounting for between 85 and 95 per cent of all cases, according to Diabetes UK.

Typically, people are diagnosed with type 2 diabetes from the age of 40.

Experts suggest the rising rates of type 2 diabetes is due to the obesity epidemic – a key cause of type 2 diabetes.

Type 2 diabetes can be treated with drugs, and many people can reverse their condition by adopting a healthy lifestyle – a healthy diet and exercise.

Type 1 diabetes is less common

Type 1 diabetes is far less common, affecting around 10 per cent of adults with the disease.

It is treated with daily insulin injections or an insulin pump.

This form of the disease typically occurs in childhood, or before the age of 40 and is not linked to obesity.

“It is incredible that a safe and inexpensive vaccine may be the key to stopping these terrible diseases.”

Faustman’s team was the first group to examine reversal of advanced type 1 diabetes in mice.

They subsequently completed a successful phase one clinical trial on humans of the BCG vaccination.

They are now conducting a five-year phase two trial involving 150 people to investigate whether repeat BCG jabs can reverse type 1 diabetes in adults.

The findings were presented at the 75th Scientific Sessions of the American Diabetes Association.

We pay for your stories! Do you have a story for The Sun Online news team? Email us at tips@the-sun.co.uk or call 0207 782 4368